Hyperfoams: Energy dissipation and shock wave formation

Abstract It has been found that highly porous organic foams (hyperfoams) modeled by the Blatz–Ko and Hill hyperelastic potentials may exhibit mechanical energy loss caused by the formation and propagation of strain discontinuities arising when a portion of a faster wave pulse overtakes a slower one. This observation opens up a possibility for creating a new type of shock absorbers containing no viscous or dry friction elements. For example, the considered Blatz–Ko-type hyperelastic potential is a good material behavior model for moderately stiff polyurethane (PU) foams both at large compression and at large extension strains. The analysis utilizes a combined method consisting of the explicit time integration technique coupled with the finite element method for spatial discretization.